I have 16 feet of floor to nearly ceiling windows on the front of my house that catches the eastern rising and mid day sun.  The front half of the house is a sauna. Even with the AC set at 75 degrees the temp reading is always at 84 degrees or more.  Installed the film as directed - it was easy, especially with two people.  The film is thicker than expected and easy to handle.  I used a squeegee to smooth out the bubbles. Instant results! The next day it was 92 degrees, my thermostat was set on 77 and it was 77 degrees in the house.  I expect to see lower utility bills in the near future!  Fear of self installation held me back last summer and I suffered through the heat and high bills - so glad I got over that.  Great product! I have already told my friends with similar issues about this product.